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1.
The electronic band-structure calculations of the PdFe ferromagnet and the PdMn antiferromagnet performed in this work permit
one to conclude that the specific features of the electrical resistivity observed in the ternary PdMnxFe1−x
alloy system [the deviation from the Nordheim-Kurnakov rule ρ0(x)∼x(1−x), which is accompanied by a high maximum of residual resistivity (not typical of metals) ρ
0
m
∼220 μΩ cm at x
C∼0.8 and a negative temperature resistivity coefficient in the interval 0.5≤x≤1] are due to the microinhomogeneous (multiphase) state of the alloys and a variation in the band-gap parameter d spectrum caused by antiferromagnetic ordering of a PdMn-type phase.
__________
Translated from Fizika Tverdogo Tela, Vol. 44, No. 2, 2002, pp. 193–197.
Original Russian Text Copyright ? 2002 by Kourov, Korotin, Volkova. 相似文献
2.
The formation of induced 5d magnetic moment on Ir in Fe100−x
Ir
x
(x=3, 10 and 17) and Co100−x
Ir
x
(x=5, 17, 25 and 32) alloys has been investigated by X-ray magnetic circular dichroism (XMCD) at Ir L2,3 absorption edges. Sum rule analysis of the XMCD data show that the orbital moment of Ir is in the range of −0.071(2)μB to
−0.030(1)μB in Fe-Ir alloys and −0.067(2)μB to 0.024(1)μB in Co-Ir alloys. We find that the total moment of Ir in Fe-Ir alloys
is approximately 1/5 of the total 3d moment on Fe at all the three compositions. In contrast, the total moment on Ir in Co-Ir alloys varies between 1/6 to 1/16
of the 3d moment on cobalt. The observed trends of Ir moments and the role of interatomic exchange interactions in 5d moment formation are discussed. 相似文献
3.
A. A. Samokhvalov T. I. Arbuzova N. A. Viglin V. V. Osipov N. I. Solin S. V. Naumov V. G. Bamburov N. I. Lobachevskaya O. G. Reznitskikh 《Physics of the Solid State》1999,41(2):262-264
Mg1−x
CuxO solid solutions having an NaCl structure with 0⩽x⩽0.20 are synthesized and Cu-Mg1−x
CuxO structures are prepared for superconductivity studies. The magnetic susceptibility χ, electron paramagnetic resonance (EPR), and electrical conductivity of the solid solutions are studied at temperatures of
5–550 K. It is shown that χ
−1(T) obeys the Curie-Weiss law with a paramagnetic Curie temperature Θ close to zero and an effective magnetic moment μ
eff=1.9 μ
B, close to the 1.73 μ
B of a Cu2+ ion with spin S=1/2. The width ΔH of the EPR line depends weakly on temperature and increases as x is raised. The volume narrowing of the EPR linewidth ΔH is used to estimate the exchange interaction parameter, 3×10−4 eV. The g-factor is close to 2 and is temperature independent. The electrical conductivity of Mg1−x
CuxO at T=300 K is ≈10−11–10−12 Ω−1 cm−1 for x=0 and increases to 10−5–10−6 Ω−1 cm−1 for x=0.15–0.20. The conductivity is p-type. Magnetic shielding is observed in Cu-Mg1−x
CuxO structures with x=0.15 and 0.20. The possible connection of this phenomenon with interference superconductivity in the contact layer of the
structure is discussed.
Fiz. Tverd. Tela (St. Petersburg) 41, 293–296 (February 1999) 相似文献
4.
A. A. Samokhvalov T. I. Arbuzova N. A. Viglin S. V. Naumov I. B. Smolyak A. V. Korolev N. I. Lobachevskaya 《Physics of the Solid State》2000,42(4):719-721
The problem of localized superconductivity has motivated the preparation of Mg1−x
CuxO solid solutions with NaCl structure and 0.01≤x≤0.20, as well as a study of the magnetization and magnetic susceptibility χ in the 2–400 K temperature range and in magnetic fields of up to 5 T. The temperature dependence of χ is described for all
compositions by the Curie-Weiss law, χ = C/(T − θ), where the constant C is close to the value calculated for each composition for μeff = 1.7–1.9μB, and θ is close to zero. For T < 30 K, χ(T) deviates for all compositions toward lower χ, which can be attributed to magnetic ordering of exchange-coupled clusters
in the solid solution. At T∼320–330 K, an anomaly of a diamagnetic type, i.e., a decrease of χ by 6–30% of its paramagnetic value, has been observed
for all compositions against the background of the generally paramagnetic χ(T). A discussion is presented of alternative reasons for this anomaly and of its possible connection with localized superconductivity.
__________
Translated from Fizika Tverdogo Tela, Vol. 42, No. 4, 2000, pp. 701–703.
Original Russian Text Copyright ? 2000 by Samokhvalov, Arbuzova, Viglin, Naumov, Smolyak, Korolev, Lobachevskaya. 相似文献
5.
Yu. F. Popov A. M. Kadomtseva G. P. Vorob’ev V. A. Timofeeva D. M. Ustinin A. K. Zvezdin M. M. Tegeranchi 《Journal of Experimental and Theoretical Physics》1998,87(1):146-151
The field dependence of the magnetoelectric effect and longitudinal magnetostriction of Ga2−x
FexO3 single crystals is studied in magnetic fields up to 200 kOe in the temperature range from 4.2 to 300 K. It is shown that
the magnetoelectric effect in these materials is determined mainly by the toroidal moment T and is not related to magnetostriction, as was previously theorized. A new method for determining the toroidal moment by
measuring the electric polarization in a strong magnetic field is proposed. The value of the toroidal moment of the unit cell
in Ga1.15Fe0.85O3 is calculated: T=(T
a
,0,0), where T
a
=24.155μ
B
Å per unit cell. Experimental data are analyzed using a theory of toroidal spin ordering, which gives good agreement with
experiment.
Zh. éksp. Teor. Fiz. 114, 263–272 (July 1998)
Deceased. 相似文献
6.
Mail Tagiyev Farkhad Samedov Sohrap Samedov 《International Journal of Infrared and Millimeter Waves》1997,18(9):1813-1820
Thin films of Bi85Sb15 solid solution wich can be used in thermoelectric devices for cooling and stabilizing the temperature of Gann and Impatt
diodes have been obtained by extrusion method. They have surface roughness in the range 10–80μm, dielectric lossestan δ ∼ 10−3 at 10 GHz, thermal conductivityβ ∼ 4x102
W / (M · K).
Anisotropy of electroconductivityσ, thermoelectric powerα and Hall coefficientsR
H of lead doped extruded Bi85Sb15 samples has been investigated in the temperature range between 77 K and 300 K and in the presence of magnetic fieldH up to ∼ 74×104 A/m. It is shown that the value and sign of the anisotropy coefficient essentially depend on heat treatment and impurity
concentration. Experimental results are explained taking into account a crystal structure of Bi85Sb15, formation of texture and generation of deformation defects. 相似文献
7.
G. A. Sukach P. F. Oleksenko A. B. Bogoslovskaya Yu. Yu. Bilinets V. N. Kabatsii 《Technical Physics》1997,42(9):1044-1047
A study is made of the excess-energy relaxation processes and the mechanisms responsible for overheating of the active zone
of infrared emitters made from nonisoperiodic structures with stressed InGaAs layers and from nearly isoperiodic InAsSbP structures
and emitting in the wavelength range λ=2.5–5.0 μm are investigated. The relationship between the overheat ΔT of the active zone of the structure and Auger processes is established for In1−x
GaxAs infrared emitters. It is shown that the efficiency of Auger recombination decreases as x increases in the interval 0–0.09, promoting a sharp reduction in ΔT. At x>0.09 the efficiency of CHHS Auger processes decreases exponentially, but an increase in the density of dislocations due to
the appreciable value (∼6.9%) of the lattice mismatch parameter causes ΔT to increase, but slowly.
Zh. Tekh. Fiz. 67, 68–71 (September 1997)
Deceased. 相似文献
8.
The B-site substituted perovskite solid solution systems Li3xLa0.67−xREyTi1−2yPyO3 (RE=Sc, Y, Nd, Sm, Eu, Yb) have been investigated. Perovskite solid solutions formed in the range of x=0.10, y<0.10 for RE=Sc3+, Y3+, Yb3+, x=0.10, y≤0.05 for RE=Nd3+, Sm3+, Eu3+. Li0.3La0.57Nd0.05Ti0.9P0.05O3 has the highest bulk conductivity of 4.31×10−4 S·cm−1 and the highest total conductivity of 2.52×10−4 S·cm−1 at room temperature in all prepared compositions. The compositions have low activation energies of about 24–30 kJ/mol in
the temperature ranges of 298–523 K. SEM studies showed that the sample made by solid-state reaction has a sphere-like morphology
and a rough particle with particle size of about 50 μm. The research results also indicated that the reaction temperature
decreases and the electrochemical stabilities of the titanate-based perovskite-type solid solutions are improved by using
RE3+ and P5+ replaced Ti4+ on B-site in the Li3xLa0.67−xTiO3 parent. 相似文献
9.
T. N. Mamedov V. N. Duginov A. V. Stoykov I. L. Chaplygin D. Herlach U. Zimmermann V. N. Gorelkin J. Major M. Schefzik 《JETP Letters》1998,68(1):64-70
The residual polarization of negative muons in crystal silicon samples with phosphorus (P: 1.6×1013 cm−3) and antimony (Sb: 2×1018 cm−3) impurities is investigated. The measurements are made in a 1000 G magnetic field oriented in a direction transverse to the
muon spin in the temperature range 4–300 K. The relaxation rate and shift of the precession frequency in the silicon sample
with the phosphorus impurity are measured more accurately than previously. It is found that in antimony-doped silicon the
acceptor center
μ
A1 at temperatures below 30 K can be in both ionized and neutral states. The experimental data are interpreted on the basis
of spin-lattice relaxation of the magnetic moment of an acceptor center, formation of acceptor-donor pairs, and recombination
of charge carriers at the acceptor. Preliminary measurements showed a nonzero residual polarization of negative muons in germanium.
Pis’ma Zh. éksp. Teor. Fiz. 68, No. 1, 61–66 (10 July 1998) 相似文献
10.
R. N. Kyutt 《Physics of the Solid State》1997,39(7):1052-1056
Double-and triple-crystal diffractometry have been used to study structural perfection of a ∼1 μm-thick Ga1−x
InxSb1−y
Asy epitaxial film (x=0.9, y=0.8) on GaSb. It is shown that scattering from samples of this system can be divided into coherent and diffuse. The arrangement
of reciprocal-lattice points of the film and substrate in the two-dimensional intensity distribution for asymmetrical reflections
argues for the absence of elastic-strain relaxation. No dislocation networks are formed, and the diffuse scattering is produced
by Coulomb-type defects. Localization of diffuse scattering in reciprocal space suggests that these defects reside in the
epitaxial film. The diffuse-scattering distribution in asymmetrical reflections is shown to be anomalous; namely, it extends
in a direction parallel to the surface and is split into two maxima. Schemes have been proposed and realized for measuring
integral distributions of diffracted intensity along the surface and perpendicular to it, and their potential for studying
diffuse scattering from defects is explored.
Fiz. Tverd. Tela (St. Petersburg) 39, 1188–1193 (July 1997) 相似文献
11.
We present the local density approximate+Gutzwiller results for the electronic structure of Ca1-xSrxVO3. The substitution of Sr2+ by Ca2+ reduces the bandwidth, as the V—O—V bond angle decreases from 180° for SrVO3 to about 160° for CaVO3. However, we find that the bandwidth decrease induced by the V—O—V bond angle decrease is smaller as compared to that induced by electron correlation. In correlated electron systems, such as Ca1-xSrxVO3, the correlation effect of 3d electrons plays a leading role in determining the bandwidth. The electron correlation effect and crystal field splitting collaboratively determine whether the compounds will be in a metal state or in a Mott-insulator phase. 相似文献
12.
A. V. Voitsekhovskii A. G. Korotaev A. P. Kokhanenko D. V. Grigor’ev V. S. Varavin S. A. Dvoretskii Yu. G. Sidorov N. N. Mikhailov N. Kh. Talipov 《Russian Physics Journal》2006,49(9):929-933
The dynamics of accumulation of electrically active radiation defects under ion doping of epitaxial Cd
x
Hg
1−x
Te films is studied for various distributions of film composition in the implantation region. The epitaxial films were irradiated
by boron ions at room temperature in the continuous regime, with the dose ranging within 1011−3·1015 cm−2, energy — 20–150 keV, and ion current density — j = 0.001–0.2 μA·cm−2. It is found that the natural logarithm of the introduction rate of electrically active radiation defects linearly depends
on the epitaxial-film composition in the range of mean projected path of implanted ions. An analysis of the experimental data
shows that the dynamics of accumulation of electrically active radiation defects is determined by the epitaxial-film composition
in the implantation region.
__________
Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 9, pp. 25–28, September, 2006. 相似文献
13.
A. V. Povarov 《Physics of Atomic Nuclei》2007,70(5):871-878
On the basis of astrophysical data on the neutrino magnetic moment, μ
ν
< 3 × 10−12
μ
B
, constraints on the scalar-leptoquark masses are found within the minimal model involving four-color symmetry. It is shown
that data on the neutrino magnetic moment are compatible with the mixing-parameter range that admits the existence of scalar
leptoquarks whose masses are below 1 TeV, reaching experimental limits obtained from direct searches. In the case of mass
degeneracy for the scalar leptoquarks S
m
of electric charge Q = 2/3, the constraint m
S
m
> 330 GeV is obtained, which is independent of the mixing parameters of the model. The results are compared with the predictions
of other leptoquark models.
Original Russian Text ? A.V. Povarov, 2007, published in Yadernaya Fizika, 2007, Vol. 70, No. 5, pp. 905–911. 相似文献
14.
I. P. Studenyak M. Kran’chets L. M. Suslikov D. Sh. Kovach 《Optics and Spectroscopy》2003,95(3):427-430
The piezobirefringence of uniaxial γ1-(GaxIn1−x
)2Se3 crystals (x=0.3, 0.4) was investigated in the spectral range 0.6–1.1 μm at temperatures from 77 to 295 K. It is shown that uniaxial compression
leads to a linear decrease in the birefringence, whereas a decrease in temperature reduces the effect of piezobirefringence.
The baric changes in the birefringence are attributed to the baric changes in the contribution of the edge transitions to
the total birefringence.
__________
Translated from Optika i Spektroskopiya, Vol. 95, No. 3, 2003, pp. 458–461.
Original Russian Text Copyright ? 2003 by Studenyak, Kran’chets, Suslikov, Kovach. 相似文献
15.
S. T. Davitadze S. N. Kravchun B. A. Strukov S. A. Taraskin B. M. Gol’tsman V. V. Lemanov S. G. Shul’man 《Physics of the Solid State》2000,42(10):1887-1890
The heat capacity and heat conductivity of Ba1−x
SrxTiO3 (x=0.2, 0.5, 0.8) polycrystalline films 1.5–2.0 μm thick on a massive substrate have been studied by the ac hot-probe method
for three-layer systems (conducting probe-dielectric film-substrate) at temperatures ranging from 100 to 400 K. It is found
that the thermal properties exhibit anomalies in the phase transition range.
__________
Translated from Fizika Tverdogo Tela, Vol. 42, No. 10, 2000, pp. 1839–1841.
Original Russian Text Copyright ? 2000 by Davitadze, Kravchun, Strukov, Taraskin, Gol’tsman, Lemanov, Shul’man. 相似文献
16.
S. N. Mustafaeva 《Physics of the Solid State》2004,46(6):1008-1010
Frequency dependence of the dissipation factor tanδ, the permittivity ɛ, and the ac conductivity σac across the layers in the frequency range f=5×104−3×107 Hz was studied in layered TlGaS2 single crystals. A significant dispersion in tanδ was observed in the frequency range 106−3×107 Hz. In the range of frequencies studied, the permittivity of TlGaS2 samples varied from 26 to 30. In the frequency range 5×104−106 Hz, the ac conductivity obeyed the f
0.8 law, whereas for f>106 Hz σac was proportional to f
2. It was established that the mechanism of the ac charge transport across the layers in TlGaS2 single crystals in the frequency range 5×104−106 Hz is hopping over localized states near the Fermi level. Estimations yielded the following values of the parameters: the
density of states at the Fermi level N
F=2.1×1018 eV−1 cm−3, the average time of charge carrier hopping between localized states τ=2 μs, and the average hopping distance R=103 ?.
__________
Translated from Fizika Tverdogo Tela, Vol. 46, No. 6, 2004, pp. 979–981.
Original Russian Text Copyright ? 2004 by Mustafaeva. 相似文献
17.
We have investigated the deposition of 91% ZrO2 − 9% Y2O3 thin films by a variety of sputtering techniques for the application as electrolytes in thin film solid oxide fuel cells.
The deposition by RF sputtering was accomplished by using an oxide target of the desired composition. The deposition rate
in these initial tests was limited to 0.5 μm/hr and the morphology of the film was substantially modified by deposition rate
and substrate temperature. Using DC magnetron sputtering we deposited metallic films from a metallic target with the desired
chemical composition. We introduced oxygen into the sputtering chamber to reactively deposit the desired 91% ZrO2 − 9% Y2O3 thin films; however, we encountered problems with target oxidation and growth rate reproducibility. We subsequently demonstrated
that controlled oxidation of the metallic films could result in adhering, non porous yttria stabilized zirconia films.
Paper presented at the 3rd Euroconference on Solid State Ionics, Teulada, Sardinia, Italy, Sept. 15–22, 1996 相似文献
18.
A model is proposed for the thermal and electrical responses of films of the high-T
c superconducting material YBa2Cu3O77−x
to current and optical pulses. Numerical calculations are compared with experimental data for current pulses of duration
100 μs and laser pulses of duration 0.1 ns; this yields improved data on the thermal conductivity of thin YBa2Cu3O77−x
films (1.5–2 W/m·K) and thermal resistance of the film-substrate contact (5×10−8m2·K/W) in the neighborhood of the superconducting transition. This model can be used for optimizing the film structure parameters
and control regimes for switching elements for pulses lasting longer than 0.1 ns.
Zh. Tekh. Fiz. 69, 77–82 (October 1999) 相似文献
19.
M. P. Breijo C. Rey S. Castro M. Sánchez M. A. Señarís-Rodríguez J. Mira A. Fondado J. Rivas 《Ionics》1998,4(3-4):267-274
We have used three soft-chemistry methods for the efficient preparation of Ln1−xSrxCoO3 samples, adapting the combustion and the liquid-mix methods for the synthesis of the Ln = La and Gd compounds, respectively,
and the preparation of Nd1−xSrxCoO3 by the nitrate decomposition method.
We report the magnetic and electrical properties of these relatively small particle-size materials, specially in the case
of the Ln = La and Ln = Nd series (d≈0.2 μm and 0.5 μm, respectively), and we compare them to those displayed by the corresponding
compounds prepared at higher temperatures. The compounds here obtained are ferromagnetic for x≥0.15 when Ln = La and for x≥0.20
when Ln = Nd and Gd. Their resistivity decreases as the doping degree increases. And, very interestingly, for compositions
0.20<x≤0.45, when Ln = La, and for x=0.40, when Ln = Nd, they show M-I transitions as the temperature rises. These are very
sensitive to the application of electrical current and its polarity and the presence of magnetic fields, displaying peculiar
behaviors.
Paper presented at the 5th Euroconference on Solid State Ionics, Benalmádena, Spain, Sept. 13–20, 1998. 相似文献
20.
I. M. Batyaev 《Journal of Applied Spectroscopy》1997,64(5):620-632
An attempt was made to describe and show the possibilities of new inorganic neodynium- and uranium-activated laser liquids:
SO2-GaCl3-NdCl4; SO2Cl2-GaCl3-NdCl3-UO2Cl2; POCl2-MCln-NdCl3-UO2Cl2 for development and synthesis of direct nuclear reaction-excited lasers. Luminescence data presented in the work were used
to calculate the luminescence parameters of the laser liquids such as oscillator strengths f, probability of spontaneous radiation
A, intermultiplet luminescence branching coefficient β, cross-section for induced radiation σ, luminescence decay time τ,
quantum yield η, and others. It is shown that the oscillator strengths of the normal absorption bands of Na3+, which play the main part in the pumping processes, exceed the oscillator strengths of Na3+ for aqueous and many other nonaqueous systems. In the luminescence excitation spectra of the Na3+ ion, bands are isolated in the range 400–1000 nm atλ
rec
=1.06 μm. With excitation, luminescence occurs through the4F3/2→4I9/2,11/2.13/2 channels. Luminescence spectral data are related to the lasing parameters. The threshold lasing energy is∼18 J/cm3. For a resonator with mirros h1=100% and h2=20, 40, 56, and 80%, the lasing energy is∼20–120 MJ/cm3 in the pumping energy range 18–180 J/cm3. The differential efficiency is ∼0.2% The substantial angular radiation divergence (θ∼4·10−2 rad) and strong thermostatic distortions that occur in the active element (dn/dT≈−1.9·10−4K−1) are a disadvantage of laser liquids. It is shown that operation of neodymium- and uranium-activated inorganic liquid lasers
is stable under the present conditions.
A. I. Gertsen Russian State Pedagogical University, Moika Embankment, 48, St. Petersburg, 191186, Russia. Translated from
Zhurnal Prikladnoi Spektroskopii, Vol. 64, No. 5, pp. 607–619, September–October, 1997. 相似文献